Question: In a single-slit diffraction pattern, what is the angular width of the central maximum if the slit width is 0.5 mm and the wavelength of light is 500 nm?

Options:

1. 0.1 rad
2. 0.2 rad
3. 0.3 rad
4. 0.4 rad

Correct Answer: 0.2 rad

Solution:

Angular width = 2λ/a. Here, a = 0.5 mm = 500 μm, so angular width = 2 * 500 nm / 500 μm = 0.002 rad = 0.2 rad.